AES Convention Papers Forum

Subjective Evaluation of Gating Methods for Use with the ITU-R BS.1770 Loudness Algorithm

Loudness measurements using ITU-R Recommendation BS.1770 can be biased downwards relative to the perceived loudness level when periods of silence and/or low level signals are present in the program being measured. To address this, it has been proposed that some form of gating be added to the loudness algorithm. To evaluate various gating methods, a formal subjective test was conducted to measure the subjective loudness of broadcast material. The results of the subjective test were used to assess the performance of the gating technique proposed by the EBU P/LOUD expert group on loudness. The study further explored the effect of gating threshold and analysis window size on the accuracy of the objective measurements. While the use of gating did improve the accuracy of the loudness algorithm no single combination could be found that satisfied all scenarios.